The image captured by the NASA/ESA/CSA James Webb Space Telescope showcases the H II region N79 in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. This nebula, composed of ionized interstellar atomic hydrogen, is observed through Webb’s Mid-InfraRed Instrument (MIRI). N79, a vast star-forming complex spanning about 1630 light-years in the largely unexplored southwest region of the LMC, is considered a younger counterpart to the well-known 30 Doradus (Tarantula Nebula), another recent target of the Webb telescope. Research indicates that N79 has exhibited a star formation efficiency twice that of 30 Doradus over the past 500,000 years.
This specific image focuses on N79 South (S1), one of the three giant molecular cloud complexes. The pronounced ‘starburst’ pattern surrounding the bright object is a result of diffraction spikes, common artifacts in telescopes using mirrors to collect light, such as the James Webb Space Telescope (Webb). In Webb’s case, the hexagonal symmetry of its 18 primary mirror segments produces six prominent starburst spikes. These patterns are particularly noticeable around intensely bright and compact objects where light originates from a single source. Most galaxies, despite appearing small to our eyes, lack the brightness and concentration to exhibit such patterns.
In the MIRI-captured longer wavelengths of light, the James Webb Space Telescope reveals the glowing gas and dust within N79, showcasing the region’s intricate details. Mid-infrared light, unlike shorter wavelengths, penetrates deeper into the clouds, avoiding absorption or scattering by dust grains in the nebula. Notably, some protostars that are still embedded in the region are visible in this field.
Astronomers find star-forming regions like N79 intriguing because their chemical composition resembles that of massive star-forming regions observed when the Universe was only a few billion years old, during the peak of star formation. Unlike star-forming regions in our Milky Way, which are not producing stars at the same intense rate as N79 and have a different chemical composition, N79 offers a unique opportunity for astronomers to study and compare star formation. Webb’s deep observations of distant galaxies in the early Universe further enhance this comparative analysis.
The observations of N79 are part of a comprehensive Webb program focused on studying the evolution of circumstellar discs and envelopes around forming stars, spanning a broad mass range and different evolutionary stages. Webb’s exceptional sensitivity allows scientists to make groundbreaking detections, including the identification of planet-forming dust discs around stars with masses similar to that of our Sun, situated in the Large Magellanic Cloud. In this image, various wavelengths are represented: 7.7-micron light in blue, 10 microns in cyan, 15 microns in yellow, and 21 microns in red. These wavelengths, captured through 770W, 1000W, 1500W, and 2100W filters respectively, provide valuable insights into the intricate details of the region’s composition and structure.
